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United States Patent ELEVATOR SYSTEMS HAVING BAfiEMENT SERVICE John Suozzo, Pararnns, and Henry C. Savino, Hackerssack, N. J., assignors to Westinghouse Electric Qnrpm ration, East Pittsburgh, Pa., a corporation of Pennsylvania Application ()ctober 11, B54, Serial No. 461,634

21 Claims. (Cl. 187-29) This invention relates to elevator systems wherein an elevator car usually operates between predetermined floors and wherein the elevator car may be assigned under certain conditions to serve one or more extension floors, and it has particular relation to an elevator system employing a plurality of elevator cars usually operating to serve predetermined floors located above one or more basement floors but capable of providing service for the basement floor or floors.

Aspects of the invention are applicable to elevator systems employing one or more elevator cars for serving any desired number of principal floors and any desired number of extension floors. However, the invention may be described adequately with reference to an elevator system employing tour elevator cars for providing service to a structure having a subbasement floor, a main-basement floor located above the subbasement floor, a lowerterminal floor located above the main-basement floor, an upper-terminal floor located above the lower-terminal floor and a plurality of intermediate floors located between the terminal floors. The elevator cars usually operate between the terminal floors. Conveniently, a dispatcher is associated with at least the lower-terminal floor for the purpose of successively selecting elevator cars to be dispatched towards the upper-terminal floor. Although the invention may be applied to elevator systems of the carattendant type, the invention is particularly desirable for elevator cars designed for operation without car attendants and will be described for the latter type of system.

In accordance with the invention, the elevator cars usually operate between the lower and upper terminal floors or landings. If a passenger within an elevator car capable of serving a basement floor registers a call for the basement floor, such car proceeds to the basement floor. If a prospective passenger at one of the floors desires to proceed to or from a basement floor and several elevator cars are capable of providing the desired service, one of the available elevator cars is selected to provide the desired service in accordance with a program providing optimum efliciency for the system. For example, if certain of the elevator cars may provide service for all of the basement floors and certain of the elevator cars may provide service only for one of the basement floors, it is preferable to assign for basement service an elevator car capable of serving all of the basement floors.

Certain predetermined conditions determine the availability of cars for basement service. If a plurality of preferred cars are available to provide the desired basement service and are in different predetermined conditions, one of the preferred cars is assigned for basement service which is in a predetermined condition assuring optimum efliciency for such assignment. To illustrate such predetermined conditions, the following three conditions may be considered:

1. An elevator car is located at the lower-terminal floor but has not been selected by the dispatcher to leave the lower-terminal floor.

2. An elevator car is displaced from the upper-terminal floor and is traveling down.

3. An elevator car is located at the lower-terminal floor, is selected by the dispatcher to leave the lower-terminal floor and has no call for service registered by a passenger within such elevator car. These conditions are preferred in the order of their listing. Thus, if three elevator cars were available, each in a separate one of the three con ditions, the elevator car in the first listed condition would be preferred for assignment for elevator service to a basement floor.

Preferably, if an elevator car is in the basement zone at a time when a demand for elevator service is received from one of the basement floors, no other elevator car is assigned at such time to provide basement service.

It is contemplated further that under some conditions, it may be desirable to modify the number of elevator cars available for basement service. For example, during an tip-peak period when large numbers of prospective passengers desire to be carried up from the lower-terminal floor or during a down-peak period when large numbers of prospective passengers desire to be carried down from upper floors to the lower-terminal floor, it may be desirable to decrease the number of elevator cars which are available for basement service.

in a preferred embodiment of the invention, the elevator cars capable of providing basement service are scanned and the predetermined conditions of the elevator cars are scanned when a demand for basement service is received. The order of scanning is such that an elevator car capable of providing service for all of the basements is scanned before an elevator car capable of providing elevator service for only part of the basement floors. In addition, the conditions are scanned in the order of their desirability. The first available elevator car located during the scanning time is assigned to provide the desired elevator service for a basement floor.

If no elevator car is found to be available during a complete scanning cycle, the scanning is interrupted until an elevator car becomes available for assignment to provide basement service.

In a preferred embodiment of the invention, if an intending passenger at the lower terminal floor registers a down floor call and fails to enter an elevator car assigned to provide basement service in response to his call, the assignment of the elevator car to provide basement service is cancelled.

It is, therefore, an object of the invention to provide an efficient elevator system capable of serving principal stations, landings or floors of a structure and extension stations, landings or floors of a structure.

It is a further object of the invention to provide an elevator system having a plurality of elevator cars capable of serving principal floors of a structure and extension floors of a structure with apparatus for selecting an elevator car to provide service for an extension floor with minimum loss in efiiciency of the elevator system.

It is also an object of the invention to provide an elevator system having a plurality of elevator cars for serving principal and extension floors of a structure with apparatus for selecting from available cars in different conditions an elevator car for serving an extension floor, the selection being made in a predetermined order dependent on certain conditions.

It is an additional object of the invention to provide an elevator system having at least one elevator car capable of serving a plurality of principal floors and a plurality of extension floors and having at least one elevator car capable of serving part only of the extension floors with apparatus responsive to a call for service from an extension floor for assigning the former elevator car, if available, to provide such service.

It is another object of the invention to provide a system for scanning elevator cars for the purpose of selecting one or more elevator cars for predetermined operation.

It is a still further object of the invention to provide a system for selecting elevator cars for predetermined operations and for modifying the elevator cars available for selection during certain periods.

It is a further object of the invention to provide an elevator system wherein an assignment of an elevator car to provide basement service is cancelled under certain conditions.

Other objects of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Figures 1, 2, 3, 4 and 6 are schematic views with circuits' shown in straight line form of an elevator system embodying the invention;

Figs. 1A, 2A, 3A, 4A and 6A are key representations showing relays and switches employed in the elevator system of Figs. 1, 2, 3, 4 and 6. If Figs. 1A, 2A, 3A, 4A and 6A are horizontally aligned respectively with Figs. 1, 2, 3, 4 and 6, it will be found that corresponding relay windings and relay contacts of the two sets of figures are substantially in horizontal alignment; and

Fig. is a schematic view, with parts shown in elevation, of a stepping switch suitable for the system of Figs. 1 to 4.

In order to facilitate the orderly presentation of the invention, a number of conventions have been adopted. Although the invention may be incorporated in an elevator system having any desired number of elevator cars serving a structure having any desired number of floors or landings, it will be assumed that the invention is incorporated in an elevator system having four elevator cars serving a structure having eight floors or landings including a main-basement landing and a subbasement landing located below the main-basement landing. The elevator cars are designated by the reference characters A, B, C and D. Inasmuch as the circuits associated with the four elevator cars are largely similar, it will suffice to show primarily the circuits associated with the elevator cars A and B. However, certain components associated with the elevator cars C and D also will be referred to. Distinctions between the circuits for the elevator cars will be pointed out below.

The first landing or street landing or floor is designated a lower-terminal landing and the sixth landing or floor is designated an upper terminal landing. The elevator car A is assumed to be capable of serving all landings whereas the elevator car B is assumed to be capable of serving all landings except the subbasement.

Because of the similarity of the circuits and components associated with the four elevator cars, components associated with the elevator cars B, C and D will be identified by the same reference characters employed for the components associated with the elevator car A preceded by the appropriate letter B, C or D. For example, the relays N, BN, CN and DN. are associated respectively with the elevator cars A, B, C and D. The discussion will be directed primarily to the elevator car A and its circuits.

Relays and switches employed for the elevator system may have front or make contacts and back or break contacts. Front or make contacts of a relay are closed when the relay is energized and picked up. The contacts are open when the relay is deenergized and dropped out. Back or break contacts of a relay are closed when the relay is deenergized and dropped out. The back or break contacts are open when the relay is energized and picked up. I

Each set of contacts of a relay or switch is designated by the reference character employed for the relay or switch followed by a suitable numeral specific to the set of contacts. For example, the reference characters U1 and U3 designate the first and third sets of contacts respectively associated with the up switch U of the elevator car A. In the drawings, all relays are shown deenergized.

In order to further facilitate the presentation of the invention, certain apparatus specific to car A and certain apparatus common to all of the elevator cars are set forth as follows:

Apparatus specific to elevator car A:

Vspeed relay Uup switch Mrunning relay Ddown switch G-inductor hold relay E-inductor slowdown relay F-inductor stop relay W--up preference relay X-down preference relay 70Tnon-interference relay DR--door relay Hcar-call relay Tcar-call stop relay Z-floor-call stop relay LLterminal relay Nloading relay Sstart relay RBbasement service relay 98OSservice relay RBZbasement zone relay 1CR to 6CRcar-call registering relays RBK-basement running relay RBT-basement timing relay 0 Apparatus common to all cars:

Figure 1 Fig. 1 shows the elevator cars A and B and certain control circuits associated therewith. The elevator car A will be assumed to be stopped at the second floor of the structure whereas the elevator car B will be assumed to be stopped at the fifth floor of the structure. With these exceptions, the circuits and mechanisms associated with the two elevator cars are similar and will be understood by reference to those associated with the elevator car A. Circuits for the elevator car A are shown in the left-hand column of Fig. l.

The elevator car A is connected by a rope or cable 10 to a counterweight 11. The rope 10 passes over a sheave 12, which is secured to a shaft 13 for rotation therewith. The shaft 13 is rotated by a motor 14 which may be of any conventional type. For present purposes, it will be assumed that the motor 14 is a direct-current motor having its armature 14A secured to the shaft 13 and having a field winding 14F which is permanently connected across two direct-current buses L1 and L2 which supply direct-current energy for the control circuits.

The elevator car A has therein a plurality of normallyopen car-call push buttons sbc, mbc, and 10 to 60 which are actuated for the purpose of registering calls respectively for the subbasement floor, the main-basement floor and the first to sixth floors as desired by passengers entering the elevator car. The elevator car B does not serve the subbasement and does not have a push button corresponding to push button sbc. To permit registration of calls for service by prospective passengers located at the various floors served by the elevator cars, push-button stations are located at such floors. Such a station is shown in Fig. 1 for the third floor. It includes a normallye p'e'n tip-floor can push button 3U which is pressed by a prospective passenger desiring elevator service in the up direction. A similar push button is located at each floor from which service in the up direction may be desired. The station also includes a normally-open push button 3D which is pressed by a prospective passenger desiring elevator service in the down direction. A similar push button is located at each floor from which elevator service in the down direction may be desired. The numeral of the reference characters (as 3D or 3U) indicates the floor at which the push button is located.

The elevator car A also has mounted thereon a slowdown inductor relay E and a stopping inductor E which may be of conventional construction. The slowdown relay E has two sets of break contacts E1 and E2 associated therewith. The relay has a normally incomplete magnetic circuit and initial energization of the winding of the relay alone does not initially open the associated contacts. However, if the slowdown relay E reaches an inductor plate UEP located in the hoistway of the elevator car while the winding of the relay is energized, the contacts E1 open. The inductor relay may be of the 'type which when it opens the contacts maintains the contacts open until the relay winding is deenergized even though the relay passes beyond the inductor plate. In Fig. 1, the inductor plate UEP is assumed to be mounted in the hoistway to be reached by the slowdown relay E as the elevator car A nears the third floor. If the elevator car A is to stop at the third floor, the winding of the relay E is energized and when the relay reaches the inductor plate UEP for the third floor, the contacts E1 open to initiate a slowdown operation for the elevator car. It will be understood that a similar inductor plate is similarly associated with each of the floors at which the elevator car A may stop during up travel thereof.

During down travel of the elevator car A, the inductor relay E cooperates with down inductor plates DEP to initiate a slowdown of the elevator car as it approaches a floor at which the elevator car is intended to stop. For example, if the elevator car is tostop during down travel at the third floor, the winding of the inductor relay E is energized as the elevator car nears the third floor. When the inductor relay reaches the down inductor plate DEP for the third floor, the contacts E2 open to initiate a slowdown operation of the elevator car. It will be understood that a similar inductor plate DEP is provided for each of the floors at which the elevator car A is to stop during down travel thereof.

The stopping relay F similarly cooperates with inductor plates UFP and DFP for the purpose of bringing the elevator car to a stop as it reaches a floor at which it is to stop. Thus, if the elevator car A during up travel is to stop at the third floor, the winding of the stopping relay F is energized and as the inductor relay of stopping relay reaches the stopping inductor plate UFP for the third floor, the contacts F1 open. These contacts in opening result in stopping of the elevator car at the I third floor. A similar inductor plate is provided at each of the floors for which the elevator car A is to stop during up travel thereof.

It the elevator car A is to stop at the third floor during down travel thereof, the winding of the stopping relay is energized and as the relay reaches the inductor plate DFP for the third floor, the contacts F2 open to produce a stopping operation of the elevator car at the third floor. It will be understood that a similar inductor plate is provided for each of the floors at which the elevator car A is to stop during down travel thereof.

Because of the large number of control circuits required, it is conventional practice to provide each elevator car with a floor selector 16. This selector includes a plurality of rows of contact segments mounted on the insulatin'g panel 16A. Only two rows of contact segments asb, amb and al to a5 and dn'tb and d1 to d5 are illus 6 trated in Fig. 1. (The elevator car B does not travel to the subbaser'ne'nt floor and does not require contact segmerits corresponding to contact segments asli, dmb and dsb.) These contact segments are successively engaged during travel of the elevator car respectively by brushes an and dd for the purpose of controlling the energizations of certain circuits. For example, if the elevator car A during down travel is to stop at the third floor in response to a car call, the brush aa engages the contact a3 shortly before the elevator car A reaches the third floor, to initiate a stopping operation thereof.

The brushes aa and dd are mounted on a brush carriage 16C which is mounted for movement in accordance with movement of the elevator car, but at a greatly reduced rate. In the embodiment of Fig. 1, it is assumed that the carriage 16C has threaded engagement with a screw 168 which is coupled to the shaft 13 through suitable gearing for rotation in accordance with movement of the elevator A. Consequently, as the elevator car A moves, the brushes mounted on the carriage 16C permit the energization of appropriate circuits at various points of travel of the elevator car.

Although the driving motor 14 may be energized in various ways, it will be assumed that the control of this motor is of the type commonly referred to as a variable voltage control. In such a control, a direct-current generator 17 has its armature 17A connected in a loop with the armature 14A of the motor. A series field winding 17$ for the generator also may be included in this loop. The generator has a main field winding 17F which is connected for energization from the direct-current buses L1 and L2 through a reversing switch. This reversing switch includes contacts U2 and U3 of an up switch. When these contacts are closed, the field winding is energized with. proper polarity for up travel of the elevator car. On the other hand, when contacts D2 and D3 of a down switch are closed, the field winding is energized with proper polarity for down travel of the elevator car. The energization of the field windings is completed through a resistor R1 for slow speed operation of the elevator car or through make contacts V1 of a speed relay for full speed operation of the elevator car.

The elevator car A is provided with a conventional spring-applied electromagnetically-released brake. This brake includes a brake drum 18D which is secured to the shaft 13 for rotation therewith. A brake shoe 18C magnetic armature 18A secured to the shoe 18C. The

coil 18B is connected to the buses L1 and L2 for energization either through make contacts U1 or through make contacts D1 of the up switch U or the down switch D.

The speed relay V is connected for energization from :the buses L1 and L2 through either of two paths. One of these paths includes make contacts U4 of the up switch, a limit switch 19 and the break contacts E1 of the slow-down relay. The limit switch 19 is a cam-operated normally-closed switch which is opened as the elevator car nears its upper limit of travel.

The remaining path of energization comprises the make contacts D4 of the down switch, a limit switch 20 and the break contact E2 of the slowdown relay. The limit :switch 20 may be cam operated. It is normally ICIOSEd :and is opened as the elevator car A nears its lower limit of travel.

As long as the elevator car A is running, the running :relay M is energized. This relay can be energized only .as long as the make contacts DRl of a door relay DR :are closed. These contacts are closed only as long as all of the hoistway doors and car doors for the car A are closed. Such safety provisions are well known in the art.

The running relay M initially can be energized if the break contacts LL1 are closed to indicate that the elesenses vator car is away from the lower terminal floor and if the break contacts 70T1 are closed to indicate that suflicient time, has elapsed since the last stop of elevator car A to permit discharge or entry of passengers. (If the break contacts 70T1 are not effective at the upper terminal floor, contacts similar to the contacts LL1 would be connected in series with the contacts 70T1 to open when the elevator car is at the upper terminal floor.)

Assuming that the foregoing contacts associated with the running relay M are closed, the relay may be energized initially through either of two paths. One of these paths is as follows:

L1, 70T1, LL1, W1, F1, 21, U, M, DRl, L2

Since the up switch U is energized through this path, it follows that the elevator car will be conditioned for up travel. The limit switch 21 is a normally-closed mechanically-operated switch which is opened as the elevator car A nears its upper limit of travel. When energized, the up switch U closes its make contacts US to establish a holding circuit around the contacts 70T1, LL1 and WI.

The second path for initially energizing the running relay M may be traced as follows:

L1, 70T1, LL1, X1, F2, 22, D, M, DRl, L2

Since the down switch D now is energized, it follows that the elevator car A is conditioned for down travel. The limit switch 22 is a mechanically-operated normally-closed switch which is opened as the elevator car A nears its lower limit of travel. When it picks up, the down switch D closes its make contacts D5 to establish a holding circuit around the contacts 70T1, LL1 and X1.

If the elevator car A is to be operated by a car attendant, the contacts LL1 and 70T1 may be replaced by a manually-operated switch which is closed by the car attendant when the car is to be moved from a floor at which it is stopped. However, in a preferred embodiment of the invention the automatically-operated contacts LL1 and 70T1 are employed.

The starting of the elevator car from the lower-terminal floor (assumed to be the first floor) is controlled by the make contacts S1 which are connected across the contacts 70T1 and LL1. If a dispatcher is employed for the upper-terminal floor, contacts similar to the contacts S1 may be employed for starting the elevator car from the upper terminal floor. For present purposes, it will be assumed that a dispatcher is employed only for the lower-terminal floor.

If it is desired to expedite departure of the elevator car from a floor when the car is fully loaded, a load-responsive switch LW may be connected across the contacts S1. The switch LW is designed to close only when the elevator car is fully-loaded.

The slowdown relay E, the inductor relay F, and a holding relay G are energized in parallel from the buses L1 and L2 through make contacts M1 of the running relay M. To complete an energizing circuit for these relays E, F and G, one of the following conditions must be present: First, the make contacts T1 are closed to indicate that a car call is registered for a floor which the elevator car A is approaching. Second, the make contacts Z1 are closed to indicate that the elevator car A is conditioned to stop at a floor in answer to a registered floor call for such floor.

When the holding relay G is energized, it closes its make contacts G1 to establish with the make contact M1 a holding circuit for the inductor relays E and F.

The direction of travel of the elevator car A is determined initially by an up-preference relay W and a down preference relay X. For the Lip-preference relay W to be energized, the break contacts D6 must be closed (i. e., the down. switch D is deenergized). The break contacts X2 must be closed (i. e., the down-preference relay X is deenergized). The limit switch 23 also must be closed. This switch is normally closed and is opened as the elevator car A reaches its upper limit of travel, in this case,

thesixth floor. Finally, the break contacts RBI must be closed to indicate that the elevator car is not assigned for basement service.

The down preference relay X is energized if the break contacts U6 are closed (i. e., the up switch U is deenergized), the break contacts W2 are closed (i. e., the up preference relay is deenergized) and the limit switch 24 is closed. This limit switch is normally closed and is opened as the elevator car A reaches the lower terminal floor. If the elevator car is assigned for basement service, the make contacts RB2 close to shunt the limit switch 24.

As long as the elevator car A is running, the make contacts M2 are closed to energize the non-interference re-- lay 70T. When the elevator car A stops, the contacts M2 open to deenergize the relay. However, the relay 70T has a substantial delay in dropout. This delay may be provided in any suitable manner as by connecting a resistor R2 across the relay coil. The time delay in dropout is selected to be suificient to permit discharge of passengers from the elevator car A or entry of passengers into the elevator car A after each stop.

It will be recalled that the door relay DR is connected across the buses L1 and L2 through contacts operated by each door associated with the elevator car A. If any of the doors is open, the contacts associated therewith are also open to prevent energization of the door relay DR.

' Figure 2 Figure 2 shows the call registration circuits for the elevator cars. Car call registration circuits are illustrated for the elevator carsA and B in the upper part of this figure.

It will be recalled that the elevator car A is provided with a plurality of push buttons sbc, mbc, and 10 to 60 for the purpose of registering car calls. The push button sbc is not shown in Fig. 2. (Switches controlled by push buttons in the elevator cars are shown in Fig. 3 for the basement floors for the elevator car A and for the mainbasement floor for the elevator car B.) Inasmuch as car call push buttons and associated circuits for the intermediate floors are similar, they are not illustrated in Fig. 2 for the second, third and fourth floors. Each of these push buttons has associated therewith a car call registerlng relay mbCR and 1CR to 60R, respectively. In this group only representative relays 6CR and mbCR are shown in Fig. 2A. The push buttons and call registratron relays cooperate with four rows of contact segments located onthe floor selector for the elevator car A. The contact segments asb, amb and al to a5 cooperate with the brush aa for the purpose of initiating a stopping operation of the elevator car during down travel of the elevator car respectively at subbasement floor, the mainbasement floor and the first to fifth floors. The contact segments bmb and 121 to I76 cooperate with a brush bb for the purpose of initiating a stopping operation of the elevator car during up travel of the elevator car respectively at the main-basement and first to sixth floors. A brush cc cooperates with a row of contact segments cmb and 01 to c6 and a brush dd cooperates with a row of contact'segrnents dmb and d1 to d5 for the purpose of cancelling registered car calls as they are answered respectively' during down travel and up travel of the elevator car. It will be understood that for each contact segmenathe numeral of the reference character designates the fioor-with which the contact segment is associated. (sb and mb designate the subbasement and mainbasement floors.) Thus, the reference character a1 designates the contact segment for the first floor in the a row. (As previously explained, the elevator car B does not serve the subbasement floor and does not have car call circuits for such floor.)

By reference to Fig. 2, it will be observed that when the car call push button 50 is pressed, the car call registering relay SCR is connected therethrough across the 9 buses L1 and L2. This relay closes its make contacts CR1 to establish a holding circuit around the push button. The contact segments a5 and b5 are connected through this set of contacts to the bus L1.

If the elevator car A is set for down travel, the make contacts X4 are closed. And, if the elevator car is approaching the fifth floor, the make contacts M4 of the running relay also are closed. Consequently, as the elevator car nears the fifth floor, the brush aa engages the contact segment a5 to complete the following circuit for the car call stopping relay T:

L1, H, SCRl, a5, aa, X4, T, M4, L2

The energization of the relay T initiates a stopping operation of the elevator car A at the fifth floor.

As the elevator car A continues its approach toward the fifth floor, the contact segment 05 is engaged by the brush cc. As the elevator car comes to a stop, the break contacts MS of the running relay close to complete the following cancelling circuit:

L1, H, 5CR1, SCRN, 05, cc, X5, M5, L2

The operating coil of the registering relay 5CR and the cancelling coil SCRN are wound in opposition on a common core. Consequently, energization of the cancelling coil SCRN cancels the effect of the operating coil and resets the registering relay 5CR. Preferably, as the elevator car stops at the fifth floor, the brush aa passes .slightly below the associated contact segment a5, however, the brush cc remains in engagement with the associated contact segment c5 as long as the elevator car A remains at the floor.

Next, it will be assumed that the same call is registered for the fifth floor as the elevator car A travels up towards the fifth floor. Under these circumstances, the make contacts W3 and W4 of the up preference relay are closed. As the elevator car A nears the fifth floor, the brush bb engages the contact segment b5 to complete the following circuit:

L1, H, 5CR1, b5, bb, W3, T, M4, L2

The energization of the car-call stopping relay T results in the initiation of a stopping operation for the fifth floor.

As the elevator car A continues to approach the fifth floor, the brush dd engages the contact segment d5 to complete the following circuit:

L1, H, 5CR1, SCRN, d5, dd, W4, M5, L2

The energization of the cancelling coil SCRN resets the call registering relay SCR. During the stopping operation, the brush bb preferably passes slightly above the associated contact segment b5; whereas, the brush dd remains in engagement with the associated contact segment d5 as long as the elevator car A is at the fifth floor.

The car call registering circuits for all of the intermediate floors are similar to those described for the fifth floor. For this reason and to conserve space, the intermediate floor circuits are illustrated in Fig. 2 only for the main-basement first and fifth floors. The elevator car may be stopped at the first floor under all conditions. To this end, break contacts LL5 of the terminal relay are connected across the push button through a switch 97A, to register a car call for the first floor as soon as the car leaves the first floor.

If the elevator car A is running down toward the lower terminal floor while assigned to the basement area and a stop at the lower terminal floor is unnecessary, the system may be designed to permit the car to pass the lower terminal floor without stopping. To this end, the switch 97A may be opened, and the switch 97 may be moved from the position illustrated wherein the contact segment a1 is connected to the bus through contacts 1CR1 to its upper position wherein the contact segment a1 is connected to the bus through the parallel make contacts 1CR2 and break contacts BRKI. If the elevator car is 10 to run to the basement area (contacts BRKI are open) and if no car call is registered for the lower terminal floor (contacts 1CR2 are open), the elevator car will not stop at the lower terminal floor on its down trip.

The car-call registering cincuits for the upper terminal (sixth floor) may be similar to those employed for the intermediate floors. However, since the elevator car A stops at the sixth floor only during up travel, contact segments for the sixth floor need not be provided in the a and d rows, and the contact segment b6 may be permanently connected to the bus L1. By reference to Fig. 2, it will be noted that only contact segments b6 and 06 are provided for the sixth floor.

It is assumed that the elevator car A never proceeds below the subbasement floor. Consequently, a contact segment asb in the a row is permanently connected to the bus L1 for energizing the relay T as the elevator carnears the subbasernent. Contact segments in the d, b and c rows are not required for the subbasement floor. It is assumed further that the elevator car B never proceeds below the main-basement landing, and a contact segment Bamb is connected permanently to the bus L1 to energize the relay BT as the elevator car B nears the main-basement landing. Contact segments in the Bb, Be and Ed rows are not required for the main-basement floor. The presence of a registered car call for floors above the basements is detected by the car call relay H through which the relays lCR to 6CR are energized.

The central part of Fig. 2 illustrates up-floor-call registering circuits. These circuits are operated by means of normally-open push buttons mbU and 1U to 5U common to all of the elevator cars which are located respectively at the main-basement and first to fifth floors. Inasmuch as the push buttons and associated circuits for the intermediate floors are similar, they are not shown for the first, third and fourth floors. The push buttons have associated therewith up-floor-call registering relays mbUR and lUR to SUR and cancelling coils mbURN and lURN to SURN in a manner which will be clear from the discussion of the call registering relays and cancelling coils associated with the car call push buttons.

The up-floor-call registering relays m'bUR and 1UR to EUR and their cancelling coils may be associated with contact segments for each of the elevator cars in the bank. For example, a row of contact segments em'b and 21 to 25, respectively for the main-basement and the first to fifth floors, is provided for the elevator car A and co operate with a brush ee. A brush ff cooperates with a row of contact segments fmb and f1 to f5, respectively for the main-basement and the first to fifth floors for the elevator car A.

Let it be assumed that while the elevator car A is traveling up a prospective passenger waiting on the fifth floor presses the up-iloor-call push button 5U to energize the up-floor-call registering relay SUR. This relay closes its make contact SURl to establish a holding circuit around the push button.

Since the elevator car is assumed to be traveling up, the make contacts W5 of the up-preference relay W are closed. As the elevator car A nears the fifth floor, the brush ee engages the contact segment e5 to complete the following circuit:

L1, SURl, e5, ee, W5, Z, L2

The energization of the floor call stopping relay Z initiates the stop at the fifth floor. In response to movement of the car towards the fifth floor, the brush ff engages its contact segment f5. As slow down of the elevator car is initiated, the break contacts V2 close to complete the following cancelling circuit:

L1, SURl, SURN, 15, ff, W6, V2, L2

This resets the up-floor-call registering relay SUR. As

the elevator car A comes to a stop, the brush ee preferably passes slightly above the contact segment 25.

. 11 However, the brush ff remains in engagement with the contact segment f as long as the elevator car A remains at the fifth fioor. By inspection of Fig. 2, it will be observed that the contact segment 05 is connected to the corresponding contact segments for the other elevator cars in the bank (such as contact segment BeS for the elevator car B). Similarly, the contact segment f5 is connected to corresponding contact segments (such as the contact segment BfS) for the remaining cars of the bank. Consequently, operation of the push button 5U is effective to stop the first rip-traveling elevator car which reaches the fifth floor and which is conditioned to accept the call at the fifth floor.

The up-fioor-call registering circuits for all of the floors requiring such circuits are similar. Consequently, such circuits are illustrated in Fig. 2 only for the main-basement, second and fifth floors. For this group only relays 2UR and 5UR are shown in Fig. 2A.

The lower part of Fig. 2 illustrates the down-floor-call registering circuits for the elevator cars. Down floor calls are registered by operation of normally-open push buttons MBD and 1D to 6D for the main-basement and the first to sixth floor, respectively which have associated therewith down-floor-call registering relays MBDR and IDR to 6DR and cancelling coils MBDRN and lDRN to 6DRN. Each push button cooperates with its call registering relay and its cancelling coil in the manner discussed with reference to the up-floor-call push buttons. Only relays MBDR, lDR and 6DR in this group are shown in Fig. 2A.

For the elevator car A, a row of contact segments gtmb and g1 to g5 cooperates with a brush gg'and a row of contact segments hmb and 111 to h6 cooperates with a brush hh. Let it be assumed that the elevator car A while traveling down is approaching the fifth floor at which a down floor call has been registered by operation of the push button 5D. Such operation results in energization of the down-iloor-call registering relay 5DR to close the make contacts 5DR1. Since the elevator car is traveling down, the make contacts X6 and X7 are closed.

As the elevator car A. nears the fifth floor, the brush gg engages the contact segment g5 to complete the following circuit:

L1, SDRI, g5, gg, X6, Z, L2

The energization of the floor call stop relay Z initiates a stopping operation of the elevator car A at the fifth floor. As the elevator car continues its approach, a brush hh engages the contact segment h5. of slow down of the elevator car A results in closure of the break contacts V2 to complete the followingcanceiling circuit:

L1, SDRI, SDRN, I15, hh, X7, V2, L2

The energization of the cancelling coil resets the callregistering relay SDR. Preferably, as the elevator car A comes to a stop, the brush gg passes slightly below the associated contact segment g5, but the brush hh remains in engagement with the associated contact segment I15.

The contact segment g5 is connected to corresponding contact segments (such as the contact segment BgS) of the remaining cars. Similarly, the contact segment hS is connected to the corresponding contact segments (such as the contact segment B115) for the remaining cars. Consequently, the first elevator car to approach the fifth floor while traveling down will answer a call registered by the call registering relay S'DR.

The down-floor-call registering circuits for all of the intermediate floors are similar and may be traced readily in Fig. 2. (Make contacts RBS and BRBS permit cancellation of a call registered by the relay lDR only if one of the sets of contacts is closed to indicate that one of the elevator cars is conditioned for basement service.) The dcwn-floor-call registering relays for the upper ter- The initiation I minal or sixth fioor also may be similar. However, since the elevator car A does not stop at the sixth floor during down travel, the contact segment in the g row may be omitted for the sixth floor. Also, since the elevator car B does not serve down calls from the main-basement landing, no contact segments corresponding to the contact segments gmb and bmb are provided for the car B.

Figures 3 and 5 In Fig. 3, circuits are illustrated for controlling the basement service relay RB, the service relay 9808, the basement zone relay RBZ and the upfloor-call registering relay sbUR for the subbasement floor.

The energization of the basement service relay RB is controlled in part by a stepping switch SS which is common to all of the elevator cars. This stepping switch includes an operating winding SSW and self-stepping contacts SSC which are controlled to advance a brush SSA with respect to a bank of contact segments SS1 to SS9 and a brush SSB with respect to a bank of contact segments $511 to SS1). Although the principles of stepping switches are well known in the art, it is deemed advisable to illustrate a suitable stepping switch which will be discussed with respect to Fig. 5.

In the embodiment of Fig. 5, the stepping switch SS has the bank of contact segments SS1 to SS9 arranged concentrically in a semi-circle about a shaft 80. Although only one brush SSA is illustrated in Fig. 3, two brushes diametrically oppose each other, SSA1 and SSA2 are secured to the shaft for rotation with the shaft to engage successively the associated contact segments. The shaft also carries a slip ring 81 which is connected to the brushes SSA1 and SSA2. The slip ring is connected through a brush 82 to break contacts R154. In a similar manner, brushes SSBI and 5382 are associated with the contact segments S811 to S819. Since the two sets of brushes are mounted on the same shaft 80, it follows that they operate in synchronism at all times.

in order to step the shaft St) a ratchet wheel 83 is secured to the shaft. This ratchet wheel cooperates with a pawl 84 which is mounted for reciprocation in a vertical direction, as viewed in Fig. 5. The pawl 84 is biased by a spring 85 in an upward direction as viewed in Fig. 5 for the purpose of urging the contacts SSC to their closed condition. When the winding SSW is energized, a magnetic armature 86 associated therewith is lowered relative to a fixed member 86A, as viewed in Fig. 5, for the purpose of opening the contacts SSC and moving the pawl 84 away from the ratchet wheel. When the winding thereafter is deenergized, the spring 85 returns the pawl 84 to the position illustrated in Fig. 5. During such movement of the pawl, the pawl engages the ratchet wheel for the purpose of advancing the shaft 89 one step. During this movement of the pawl, the contacts 880 reclose.

The brushes SSA1 and SSA1. are shown in Fig. 5 one step beyond their reset positions. As the shaft 80 is stepped in a clockwise direction, as viewed in Fig. 5, the brush SSA2 consecutively engages the contact segments until it reaches the contact segment SS9. The next step of the shaft 80 thereafter results in engagement of the contact segments SS1 by the brush SSA1.

A third row of contact segments is associated with a pair of brushes SSDl and SSD2 which are also operated by the shaft 80. Only one of these contact segments, S828, is employed in the circuits of Fig. 3.

Returning to Fig. 3, it will be noted that the stepping of the stepping switch is initiated by energizing the wind ing SSW through the contacts SSC. Such energization can be effected only if the break contacts RMZE are closed to indicate that no elevator car is in the basement area. If these break contacts are closed, the winding SSW then can be energized through each of several circuit arms. Thus, if a down floor call for the first floor is registered, the make contacts 1DR2 close to complete with the break 13 contacts RMZI an energizing'circuit for the winding SSW. Following energization of the Winding SSW, the winding cooperates with the self-stepping contacts SSC to step the stepping switch until the winding is either continuously energized or continuously deenergized. In a somewhat similar manner, the winding SSW is energized whenever a demand for elevator service is received requiring movement of an elevator car into the basement area. Thus, if a prospective passenger on the main-basement floor desires elevator service in the up direction, he may operate the floor call registering relay mbUR to close the make contacts mbUR2. These contacts together with the break contacts RMZl complete an energizing stepping circuit for the Winding SSW.

A call for elevator service from one of the floors requiring movement of the elevator car to the subbasement floor can be answered only by the elevator car A. Consequently, if the elevator car A is not in service, the desired service cannot be provided. If the elevator car A is placed in service, the switch 88 is closed to energize the service relay 9808. This relay closes its make contacts 98082 to render effective two floor-call registering relays. Thus, if a prospective passenger at the mainbasement floor desires to proceed in the down direction, he may operate the down push button for his floor to close the make contacts mbDRZ of the registering relay mbDR. These complete with the contacts 980S2 and RMZI an energizing stepping circuit for the winding SSW. In a similar manner, a prospective passenger at the subbasement floor may operate his push button sbU to establish With the limit switch 89 an energizing circuit for the up-fioor-call registering relay sbUR for the subbasement floor. The switch 89 normally is closed and is cam operated to open when the elevator car A reaches the subbasement floor.

In response to its energization, the relay sbUR closes its holding contacts sbURl and its make contacts sbURZ. The latter contacts complete with the contacts 98082 and the break contacts RMZI an energizing stepping circuit for the Winding SSW. If another of the elevator cars, such as the car C is arranged to serve the sub basement floor, make contacts of its service relay may be connected in parallel with the make contacts 93082 of the service relay for the elevator car A.

The winding SSW also may be energized for a resetting operation in response to closure of the make contacts RE2 of the reset relay RE.

When a call is registered resulting in energization of the winding SSW, the stepping switch SS starts to step from the reset position illustrated in Fig. 3 for the purpose of assigning an available elevator car to proceed to the basement area. Inasmuch as it is preferred to assign an elevator car capable of serving the subbasement floor, the brush SSA first engages contact segments associated with the elevator car A and continues to step until it reaches a contact segment which maintains the energization of the winding SSW.

In the present case, the three contact segments SS1, SS2 and SS3 are associated with the elevator car A and define three predetermined conditions which permit assignment of the elevator car A to answer a call requiring movement of the elevator car A to the basement area. Thus, if at the time the brush SSA engages the contact segment SS1 the elevator car A is at the lower-terminal floor, the make contacts LL6 are closed. If the elevator car A, at the same time, has not been selected. by the dispatcher to leave the lower-terminal floor, the break contacts N4 of the loading relay are closed and the stepping switch SSW is continuously energized to terminate the stepping of the stepping switch. If neither of these conditions is present, the brush SSA next steps to the contact segment SS2.

The engagement of the brush SSA and the contact segment SS2 results in continuous energization of the winding SSW only if the. switch 90 is closed to indicate ill) that the elevator car A 'isdisplaced from the upperterrninal floor, if the break contacts W8 are closed to indicate that the elevator car A is traveling down and if the make contacts 98083 are closed to indicate that the elevator car A is in service. The switch 90 is normally closed and is cam operated to open only when the elevator car A is adjacent the upper terminal floor. If one of these conditions is not present, the brush SSA steps to the contact segment SS3.

Engagement of the brush SSA and the contact segment SS3 completes an energizing circuit for the winding SSW only if the make contacts N5 are closed to indicate that the elevator car A has been selected by the dispatcher to leave the lower-terminal floor and either the make contacts X10 are closed to indicate that the elevator car A is set for down travel or the break contacts H2 are closed to indicate that no car call has been registered in the elevator car A for a floor above the basement floors. If another of the elevator cars, such as the elevator car C, is capable of serving the subbasement floor, each of the contact segments SS1, SS2 and SS3 may be followed by a corresponding contact segment associated with the elevator car C. Thus, a contact 0851 may be associated with a circuit for the elevator car C corresponding to the circuit for the elevator car A associated with the contact segment SS1. However, for present purposes, it will be assumed that only the elevator car A is capable of serving the subbasement floor. Consequently, if the elevator car A is not available for assignment to the basement area, the brush SSA next steps into engagement with the contact segment SS4 which is one of a group of three contact segments associated with the elevator car B. Assuming that the switch 91 is closed, the engagement of the brush SSA with the contact segment SS4 completes a circuit for the winding SSW if the elevator car B is at the lower-terminal floor (make contacts BLL6 are closed) if the elevator car B has not been selected by the dispatcher to leave the lower-terminal floor (break contacts BN4 are closed) and a call for elevator service has been registered by a prospective passenger at the main-basement floor (make contacts mbUR3 are closed). Instead of being completed through the contacts mbUR3, the circuit also may be completed if the elevator car A is not in service (break contacts 98054 are closed) and a call for down elevator service has been registered by a prospective passenger at the first floor (make contacts 1DR3 are closed). If the required conditions are not present, the brush SSA steps to the next contact segment SS5.

Engagement of the contact segment SS5 by the brush SSA completes an energizing circuit for the Winding SSW if the elevator car B is displaced from the upper terminal floor (switch B90 is closed), the elevator car B is proceeding down (break contacts BWS are closed), the elevator car B is in service (contacts B98OS3 are closed), and in addition, the previously discussed contacts mbUR3 are closed or the contacts 98034 and ZDR3 are closed. If the required conditions still are not present, the brush SSA steps into engagement with the contact segment SS6.

Engagement of the contact segment SS6 by the brush SSA completes an energizing circuit for the winding circuit if the elevator car B has been selected by the dispatcher to leave the lower-terminal floor (make contacts BN5 are closed) and the elevator car 13 is proceeding down (make contacts BX10 are closed) or the elevator car has no registered car call for a floor above the basement floors (break contacs EH2 are closed). In addition, the circuit must be completed through one of the previously discussed paths including the contacts mbURIi, 98054 and IDRS. Finally, if the elevator car B is not available for assignment to the basement area, the brush SSA steps into engagement with the contact segment SS7 and is energized through the break contacts 79581. The brush remains in this position until the contacts 79SS1 open to indicate that an elevator car is available for assignment for basement service whereupon the cycle is repeated.

If another elevator car such as the elevator car D is available for assignment to serve only the main-basement of the basement floors, contact segments D884, D855, and D556 may be located below the corresponding contacts for the elevator car B. These contacts are associated with circuits for the elevator car D which are similar to the circuits associated with the contact segments SS4, SS5 and SS6 for the elevator car B. However, for present purposes, it will be assumed that only the elevator car B is available for such service.

Under certain conditions it may be desirable to modify the performance of the elevator system in response to a demand for basement service. For example, during peak periods it may be advisable to decrease the number of elevator cars which may respond to a call for elevator service from one of the floors of the structure. Such a peak period may be an up-peak period wherein large numbers of prospective passengers desire to be carried from the lower terminal floor to a higher floor of the structure. As a further example, the peak period may be a down-peak period during which many passengers desire to be carried from higher floors of the structure to the lower terminal floor. Modifications of an elevator system for the purpose of expediting travel in one direction during peak periods are well known. For example, during such a period, the floors of the structure may be divided into zones with certain cars designated high-zone cars assigned to serve primarily a high zone of floors and certain elevator cars designated low-zone cars to serve a low zone of floors. As a further example, during an up-peak period the floor-call stop relay of a car may be prevented from responding to down floor calls. Thus, for the elevator car A the brushes gg and hit (Fig. 2) may be disconnected from the floor-call stop relay Z. During a down-peak period certain or all of the cars may be prevented from responding to up floor calls. Thus, the elevator car A may have its brushes ee and ff disconnected from the floor call stop relay Z during a down-peak period.

Although the peak periods may be detected by a computer responsive to traflic conditions, for present purposes it will be assumed that the peak periods are determined by a time switch TS (Fig. 3) which opens up-peak contacts UPKl during periods when an up-peak is expected. The time switch opens contacts DP1 during periods when a down-peak is expected.

If the switch 91 is opened the contact segments SS4, SS5 and SS6 are ineffective for energizing the winding SSW of the stepping switch during an up-peak period when the contacts UPKI are opened or during the down peak period when the contacts DP1 are opened. Preferably an elevator car capable of serving the subbasement floor is left in service, in this case the elevator car A. If several cars are capable of serving the subbasement and if during a peak period certain of these cars are high-zone cars and certain are low-zone cars, preferably an elevator car left in condition to serve the basement area is one of the high-zone cars.

It will be recalled that the brush SSB moves in unison with the brush SSA. Consequently, when the stepping switch moves from its reset condition, the brush SSB successively engages the contact segments SS11, S812 and S813, all of which are associated with the elevator car A. These contact segments are connected in parallel for controlling in part the energization of the basement service relay RB for the elevator car A. The relay RB preferably has a delay in pick-up which is slightly greater than the time required for the brush SSB to step from one contact segment to the next contact segment. Consequently, the relay RB does not pick up during a stepping operation of the brush SSB. The relay can pick up only if the brush stops at a contact segment for a time greater 16 than the time delay of the relay and if certain other conditions are satisfied.

Energization of the basement service relay RB also requires that the elevator car A be set for down travel (make contacts X8 are closed) or that the elevator car A be positioned at the lower terminal floor (brush 2! is in engagement with the contact segment 11). The contact segment t1 and its associated brush are mounted on the floor selector of the elevator car A.

Energization of the basement service relay RB further requires that the elevator car A be set for down travel (make contacts X9 are closed) or that no car call is registered in the elevator car A for a floor above the basement area (break contacts H1 are closed).

If another elevator car, such as the elevator car C, is connected for operation in the same manner as discussed for the elevator car A, contact segments for the elevator car C may be associated with a relay similar to the relay RB in the same manner discussed for the elevator car A. Such contact segments C8811, C8812 and CSS13 are illustrated in Fig. 3 respectively below the contact segments S511, S812 and S513, but for present purposes it will be assumed that they are not employed.

If the elevator car A is not available for assignment for basement service the brush SSB next engages one of three contact segments SS14, SS15 and $816 which are associated with the basement service relay BRB for the elevator car B in the same manner by which the contact segments S811, SS12 and SS13 are associated with the relay RB for the elevator car A. If another elevator car, such as the elevator car D is designed for operation in a manner similar to that discussed for the elevator car B, contact segments D8514, D8815 and DSS16 may be associated with a basement service relay for the elevator car D in the same manner by which the contact segments SS14, S515 and SS16 are associatedwith the relay BRB for the elevator car B. Although the contact segments DSS14, DSS15 and DSS16 are illustrated in Fig. 3 respectively below the contact segments SS14, S815 and SS16, it will be assumed that they are not employed.

The contact segments S817, S518 and 8819 are disconnected segments which merely represent stepping positions for the brush SSB.

If a car call is registered in the elevator car A while the car is set for down travel, it is desirable that the elevator car A be assigned to proceed to the basement floor. Thus, if a car call is registered for the main-basement floor, the push button mbc of Fig. 2 is operated. This push button has an additional set of contacts mbol which are shown in Fig. 3. If the contacts mbol. are closed while the elevator car A is set for down travel the relay RB is connected for energization through the circuit:

L1, mbol, X8, X9, RB, L2

Similar contacts are provided for the elevator car B.

If a car call in the elevator car A is registered for the subbasement floor a push button sbc is operated. If the elevator car A is set for down travel the following circuit is established:

L1, sbc, X8, X9, RB, L2

Since the elevator car B does not serve the subbasement floor a similar push button is not provided for the elevator car B.

When the basement service relay RB is energized it closes holding contacts RB3 which complete with a switch 92 a holding circuit for the relay. (For the present, switches 97B and B97B are assumed to be closed to shunt respectively the contacts RBT1 and BRBTl.) The switch 92 is normally biased into closed condition and is cam operated to open when the elevator car A is adjacent the subbasement floor. The corresponding switch B92 for the elevator car' B is cam operated to open when the elevator car B is adjacent the main basegized through a switch 93.

17 ment floor. .If'the switch 973 is open the holding circuit completed by the contacts RB3 includes make contacts RBT'I. Make contacts RBI- 2 also complete with the switch 92 a holding circuit for the relay RB.

The presence of the elevator car A in the basement area is detected by a basement zone relay RBZ which is ener- The switch is normally biased to closed condition and is cam operated to open when the elevator car A is below the lower-terminal floor. If the elevator car A is out of service the break contacts 98081 close to maintain the relay RBZ in energized condition.

During a resetting operation of the stepping switch the break contacts RBI and RB4 are opened to prevent a false stepping of the stepping switch.

Figure 4 In Fig. 4 circuits are illustrated for controlling the energization of the basement master relay RMZ, the reset relay RE, the availability relay 7988 and the dispatching of the elevator cars from the lower-terminal floor.

When the elevator car A is in the basement area the break contacts RBZl are closed to energize the basement master relay RMZ. Similar contacts in parallel with the contacts RBZ are provided for each of the elevator cars serving the basement area.

When the elevator car A- is assigned to proceed to the basement area the make contacts RB4 close to energize the reset relay RE. Similar contacts in parallel with the contacts RB4 are provided for each of the elevator cars serving the basement area.

If no elevator car is available for assignment to the basement area the stepping switch of Fig. 3 is permitted to complete only one cycle of operation until the availability relay 79SS picks up to indicate that an elevator car is available for assignment. For the elevator car A the relay 7 988 may be energized through either of two circuits. One of the circuits is completed when the elevator car A is in service (make contacts 98OS6 are closed) the elevator car is set for down travel (break contacts W9 are closed) and the elevator car is displaced from the upper-terminal floor (switch 94 is closed) the switch 94 is normally biased to closed condition and is cam operated to open only when the elevator car A is adjacent the upper terminal floor.

The second circuit for energizing the relay 7988 includes break contacts 7 T2 of the non-interference relay which are closed when the elevator car A has stopped at a floor long enough to discharge and load passengers, normally-open contacts LTS which are closed only when the elevator car is at the lower-terminal floor, break contacts H3 which are closed when no car call is registered for a floor above the basement area and break contacts S which are closed when the elevator car A is not being started from the lower terminal floor.

Similar contacts control the energization of the relay 7 988 for the elevator car B. However, for the elevator car B additional contacts also control the energization of the relay. Thus, the energization of the relay for the elevator car B is controlled by a switch 91A-which opens and closes with the switch 91 of Fig. 3. If the switch 91A is open, energization of the relay 79SS requires closure of the contacts UPKZ and DP2 of the time switch TS and these contacts operate respectively with the contacts UPKI and DPI of Fig. 3.

The energization of the relay 7988 by the elevator car B also requires either of two additional conditions to be fulfilled. One of theseconditions is that the elevator car A is not in service and break contacts 98OS5 consequently are closed. These contacts are shunted by a circuit which includes the break contacts mbDR3, 1DR4, sbUR3. Consequently, the shunt circuit is opened if a down floor call is registered at the main basementfloor or at the firstfloor orif an up call is registered at the subbasernent floor.

In Fig. 4, a dispatching device is illustrated which normally controls the dispatching of the elevator cars employed in the system from the lower-terminal or street floor.

The selection and timing mechanism include as one component a motor 71 whichoperates substantially at constant speed. This motor may be of any suitable type,- but for the present purposes it willbe assumed that the motor is a separately-excited direct current motor having an armature 71A which is energized from thebuses L1, LS1 through a resistor rR-Sand a field winding 71F energized through resistors R4, R5, R6 across the buses. The resistors may be shunted respectively by make contacts LL3, BLL3 and CLL3.

The motor 71 is connected through aspring-released electromagneticallyaapplied clutch 72 to a cam 73 having a protuberance for successively operating mechanical switches Y, BY, CY and DY which are associated with the respective elevator cars. The electromagnetic .clutoh can be energized only if one or more elevator cars are located at the dispatching floor which is assumed to be the first floor (one or more of the contacts LL2, BLL2, CLL2 and DLL2 are closed), and if no elevator car has been selected as the next car to leave the dispatching floor (break contacts N2, BN2, CN2 and DN2 all are closed).

The motor 71 also may be coupled through a springreleased electromagnetically-applied clutch 74 to a cam 75 which is biased towards a predetermined position by a spring 76. The cam 75, when coupled to the motor 71, is rotated against the bias of the spring to close normallyopen contacts 77 a predetermined time after the cam 75 is coupled to the motor 71. The clutch 74 can be electrically energized only if no elevator car is being started (break contacts S2, BS2, ,CS2 and D82 are closed), and if the break contacts 1810f theholding relaylS are closed. The holding relay 18 is energized upon closure ofthe contacts 77, if contacts S2 to D82 are closed, to close its make contacts 152 for the purpose of establishing a holding circuit around the contacts 77.

The presence of an elevator car at the dispatchingfloor is determined by the energization of a car-position relay for each of the elevator cars. Thus, if the switch 970 is closed a car-position relay LL for the elevator car A .is energized when the brush kk'engages the contact segment/c1. .If the switch 97C is open, the energizing circuit alsoincludes the break contacts ,RBK3.

The brush kk is operated by the floor selector for .the elevator car A to engage the contact segment k1 when the elevator car is atthe dispatching floor.

if the elevator car A is at the dispatching floor (make contacts .LL4 are closed), if it has been selected as the next carto leave the dispatching floor (switch Y is closed), and if it is not being started (break contacts S3 are closed) the loading relay N for the elevator car A is energized. The loading relay may be employed in a conventional way to permit loading of theelevator car A. For example, the loading relay when energized may operate a loading signal, such as a lamp, whichindicates that passengersmay enter the elevator car. Conveniently, the loading relayN when energized opensthe normally-closed doors of the elevator car A to permit entry of passengers into the elevator-car.

After the expiration of a time suificient for the cam 75 to close the contacts 77 and energize the relay IS, the make contacts 153 close to complete the following circuit:

L1, LL4, S, N3, 153, L2

The relay S when energized closes its make contacts S4 to establish a holding circuit around the contacts N3 and 133, and starts the elevator car A fromthe dispatchingfloor.

Operation In order to explain the over-all operation of the ,cle vat-or system it will be assumed firstthattheelevator:ears are at the first or dispatching floor when the system amass initially is energized. The cars are conditioned for opera 'tion in the up direction. For example, the elevator car A has its up-preference relay W energized. Consequently, make contacts W1 and W3 to W6 of the relay are closed, whereas break contacts W2, W8, W9 of the relay are open. Switches 97, 97A, 97B and 97C are assumed to be in the positions illustrated.

The motor 71 (Fig. 4) is energized to rotate at a substantially constant rate.

Inasmuch as the elevator cars are assumed to be at the dispatching floor, the car-position relays LL, etc. are energized.

As a result of its energization, the car-position relay LL opens its contacts LL1 (-Fig. 1) and closes its contacts.

LL2, LL3, and LL4 (Fig. 4). Closure of the make contacts LL2 completes the following circuit for the clutch 72:

L1, LLZ, 72, N2, BN2, N2, DN2, L2

The clutch now couples the motor 71 to the cam 73 for the purpose of successively closing and opening the associated mechanical switches. It will be assumed that the first switch reached by the cam is the switch Y for the elevator car A. Closure of this switch completes the following energizing circuit for the loading relay of the elevator car A:

L1, LL4, N, s3, Y, L2

The loading relay N upon energization in a conventional manner initiates opening of normally-closed doors of the elevator car A or operates a signal to permit intending passengers on the dispatching floor to enter the elevator car.

In opening, the door opens its set of contacts to deenergize the door relay DR (Fig. 1) which opens its contacts DRl without immediate eifect on system operation.

Opening of the break contacts N2 (Fig. 4) deenergizes the clutch 72. Consequently, the cam 73 is uncoupled from the motor 71. Fin-ally, the make contacts N3 close to prepare the starting rel-ay S for subsequent energizat-ion.

When the system was placed in operation, the clutch 74 was energized through the circuit:

L1, 181, 74, S2, BS2, CS2, DSZ, L2

As a result of its coupling to the motor 71, the cam 75 rotates against the bias of its spring 76 until at the expiration of the time interval allowed for loading elevator cars the contacts 77 close. The rate of rotation depends on the number of resistors R4, R and R6 con nected effectively in series with the field winding 71F. In the present case the contacts LL3, BLL3, CLL3 shunt all of the resistors and the motor rotates at a relatively slow rate. Closure of these contacts completes the following circuit:

L1, '18, 77, S2, B82, C52, D82, L2

The energized relay 1S closes its make contacts 182 to establish a holding circuit around the contacts 77. The break contacts 181 open to deenergize the clutch 74, and the spring 76 now rotates the cam to its starting position. Also, the make contacts 183 close to energize the auxiliary starting relay S through the following circuit:

L1, LL4, S, N3, 183, 1/2

leave the lower terminal floor in the manner previously set orth.

First, it will be assumed that the elevator cars are parked at the lower-terminal floor and that a passenger has entered the elevator car A at the lower-terminal floor for the purpose ofproceeding to the fifth floor.

The doors of the elevator cars may be of the manuallyopened, spring-closed type or may be of the conventional power-operated design. Upon entering the elevator car A, the passenger presses the car call push button 5c (Fig. 2) to energize the associated car-call registering relay 50R. This relay closes its self-holding contacts 5CR1. It will be assumed that the elevator car has been stopped at the lower terminal floor long enough for the relay T to time out and close its break contacts 70T1. Upon closure of the doors, the door relay DR closes its make contacts DRl to complete the following circuit:

L1, S1, W1, F1, 21, U, M, DR'l, L2

Upon energizaticn, the up switch U closes its make contacts U1 to release the elevator brake. Contacts U2 and U3 close to energize the generator field winding 17F with proper polarity for up travel of the elevator car. Contacts U4 close to complete the following energizing circuit for the speed relay V:

L1, U4, 119, E1, V, L2

The speed relay closes its make contacts V1 to shunt the resistor R1 and conditions the elevator car for full speed operation. The speed relay V also opens its break contacts V2 (Fig. 2) without immediate eflect on the system operation.

Continuing with the operation of the up switch U, the energized up switch closes its make contacts US to establish a holding circuit around the cont-acts S1 and W1. Break contacts U6 open to prevent energization there- 'through of the down preference relay X.

The elevator car A now accelerates in the up direction for the purposeof carrying the passenger to the fifth floor.

As the elevator car leaves the lower-terminal floor the brush kk (Fig. 4) leaves the contact segment k1 to deenergize the terminal relay LL. Closure of contacts LL1 (Fig. l) and opening of contacts LLZ and LL4 in Fig. 4 does not have any immediate effect on system operation. Opening of contacts LL3 introduces the resistor R21 in series with the field winding 71F to increase the speed of the motor 71. Closure of contacts LLS (Fig. 2) registers a car call for the first floor. Opening of contacts LL6 (Fig. 3) has no immediate effect on system operation.

It will be recalled that the running relay M also was energized. As a result of its cnergization, the running relay closes its make contacts to prepare the relays G, E and F for subsequent energization. Make contacts M2 close to energize the non-interference relay 70T. The non-interference relay opens its break contacts 701"! but such opening has no immediate eflect on the operation of the system.

Referring to Fig. 2, the running relay M closes its make contacts M4 and opens its break contacts M5. Such contact operations have no immediate effect on the operation of the system.

However, the approach of the elevator car A towards the fifth floor brings the brush bb (Fig. 2) into engagement with the contact segment b5 to energize the car call stopping relay T through the circuit:

L1, H, 5on1, B5, bb, W3, T, M4, L2

The car call' stopping relay closes its make contacts T: (Fig. l) to energize through the contact M1 the three relays G, E, and F in parallel. The relay G closes its make contacts G1 to establish a holding circuit around the contacts T1. 7 The operationof the relay H will be considered below.

The energization of the inductor slowdown and stopping relays E and F prepares these relays for subsequent 

